Purpose: Dynamic trunk flexion-extension testing has been proven to objectively diagnose low back pain in persons under the age of 60 years but older persons have difficulty complying with standardized movement velocity.
Methods: 190 patients and 71 matched healthy volunteers (18-90 years of age) performed modified testing by holding static positions at standing, half, and full trunk flexion.
Results: Lumbar extensor muscle activity in isometric positions was significantly higher in patients with higher activity in the oldest (60-90 years) and the middle-aged (40-59 years) but not in the youngest (18-39 years) subgroups compared to normal. There were no differences in gross trunk range of motion, half flexion relaxation ratio, proprioception, muscle activity differences between positions, and fear-avoidance behavior. The diagnostic accuracy as expressed by the area under the curve was fair (0.74).
Conclusions: Lumbar extensor muscle activity demonstrated moderate to good diagnostic value in old patients.
Keywords: Chronic back pain; Electromyography; Healthy volunteers; Kinematics; Proprioception.